1. Field of Invention
This invention relates to an improved rotating kite tail for stabilizing a kite in flight.
2. Discussion of Prior Art
A variety of rotating kite tails have existed for many years. Descriptions of rotating kite tails can be found in kite catalogs such as Into the Wind 1990 Kite Catalog, 1408 Pearl Street, Boulder, Colo. 80302, and in the Penguin Book of Kites, David Pelham Penguin Books, 625 Madison Ave. NY, N.Y. 10022.
Elongated helix tails, multi-tethered parachute shaped tails, rotating elongated wind socks, and multi-tethered elongated rotating drogue type kite tails are currently available. Rotating kite tails such as these rotate faster in higher winds. Faster rotation creates greater wind friction and drag. In this sense these kite tails are self-regulating. Multi-tethering and elongation provide the tail with directional stability. But in terms of the aerodynamics and economics of kites, multi-tethering and elongation are expensive and heavy. Kite flyers want to minimize their costs but they also want their kite to fly in as wide a range of winds as possible. A lighter, simpler, more wind responsive, higher r.p.m. rotating kite tail is needed.
U.S. Pat. No. 3,806,073 was issued to Jay. D. Christie for a kite tail that heretofor most closely addressed this need. However, Christie's kite tail utilized elongated helical fins or a combination of fins and rudders to create the aerodynamics that cause the tail to rotate and self regulate.
Elongated helical fins are relatively heavy and complex, and Christie's fin and rudder arrangement is designed in such a way that the rudders tend to flatten out and loose effectiveness in high winds unless these fins and rudders are constructed of relatively heavy, expensive material.
U.S. Pat. No. 4,778,132 was issued to Carl E. Stoecklin and John F. Stoecklin for mounting a pinwheel to a kite. A pinwheel does provide efficient rotational drag, however, the Stoecklins' did not provide for the pinwheel to trail off in the wind leeward the kite. It is the leeward tug on the aft portion of a kite, or multiple leeward tugs symmetrical about the center spine of a kite that give a kite lateral pitch stability.
Thus the Stoecklins' invention is not effective in the way a self regulating rotational kite tail is effective. U.S. Pat. No. 1,352,674 was issued to C.F. Mitchel for pinwheels. However Mitchel's pinwheel is not assembled in a manner that allows it to elongate proportional to the velocity of the wind. The windward and leeward faces of Mitchel's pinwheel are not able to separate and stretch apart in order to provide increased directional aerodynamic stability and increased structural rigidity to the blades of the pinwheel as an automatic response to wind velocity. Consequently Mitchel's pinwheel does not work as a rotational kite tail. Increasing wind velocities cause it to wobble about, turn sideways, and bend. Consequently it doesn't have the desired quality of rotating faster with increased wind velocity.
Jackson, U.S. Pat. No. 3,936,020 and Busato, French patent 958,172 both suggest propeller-like elements for use as rotational kit tails. A propeller at the end of a string used as a kite tail tends to turn sideways and to fail to rotate. This is because it has very little elongation in the direction of the wind--very little directional stability. A string of propellers can be made so that each propeller is rigid enough and has a sufficiently long bearing surface about its axis of rotation that this string of propellers do rotate about the axis of a kite tail even in high winds. However propellers designed for high winds are too heavy for low winds. And propellers designed for low winds bend and deform in high winds. Propellers and pinwheels with fixed blade depth and bearing length tend to deform undesirably with increased wind velocity. They tend to become structurally unreliable and aerodynamically unstable. What is needed an desired is an inexpensive, light weight, rotational kite tail that is truly self regulating--one that automatically deforms in a desirable way as wind speeds increase to provide increased rigidity and directional stability as well as increased drag.